Google fussion table with collect earth

Google Fusion Tables are deprecated and as you say cannot be used anymore in GEE.

Luckily the data collected with Collect Earth can still be used in GEE by uploading it as a table.

When you go in GEE Code Editor you can see that in the tab Assets you have the possibility to upload the data as a CSV (Table ) :

When you do that, there is a dialog where you have to specify that the columns for the X and Y coordinates are XCoordinate and YCoordinate

After you upload the table you can reference it in the ee.FeatureCollection using the Asset id ( where you do not need anymore the ft: prefix as that was used to indicate the data came from a Fusion Table)

Let us know if it there are issues using the data!

This is a link explaining how to work with Assets : https://developers.google.com/earth-engine/asset_manager

This is another link to a Google Earth Engine script which uses cart to classify Lansat 8 imagery. You can test it with your data by changing the line 31 ( use the Asset you have uploaded) and also line 37 where you specify what property from each feature ( or column for each line in the CSV) should be used to classify with!

Here is another link that might also be useful from the Google Earth Engine tutorial.

For more info about the classification algorithms it is better to ask in the GEE discussion group ( search in the archive before asking ).